Putter and extension device therefor

ABSTRACT

A putter-type golf club with a removable central shaft portion which allows for varying the length of the putter-type golf club without varying the mass. The putter-type golf club has a club head with a lower shaft which is removably attached to a bottom end of the central shaft portion. The putter-type golf club also has an upper shaft portion which is removably attached to a top end of the central shaft portion.

CROSS REFERENCES TO RELATED APPLICATIONS

The Present application claims priority to U.S. Provisional Patent Application No. 60/804,411, filed on Jun. 9, 2006.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a putter. More specifically, the present invention relates to a putter type golf club with an extendable portion.

2. Description of the Related Art

The golf industry has been inventing putters that make the game of golf easier for the high handicap player. One such putter is disclosed in U.S. Pat. No. 4,688,798 to David Pelz. The Pelz patent discloses a putter with an alignment means to assist a golfer in aiming a golf ball toward a hole during putting. The Pelz patent discloses using two or three golf ball shaped indicators as the alignment means. The golf ball shaped indicators may be circles, hemispheres, or complete spheres. The Pelz patent discloses positioning the indicators along a line extending rearward from the center of percussion.

Another patent that discloses an alignment means is U.S. Pat. No. 4,659,083 to Szczepanski. The Szczepanski patent discloses a group of lines that converge toward the center of the face of the putter.

Yet another patent that discloses an alignment means is Great Britain Patent Application Number 4,659,083 to Lilley. The Lilley patent also discloses a group of lines that converge toward the center of the face of a putter.

Another example is Schmidt et al., U.S. Pat. No. 5,470,068, for a Golf Putter With Dished Bottom Surfaces which discloses a putter composed of a single cast material and having a hollow interior.

Another example is Uebelhor, U.S. Pat. No. 6,086,484, which was filed on Mar. 20, 1998 for a Golf Putter Head. Uebelhor discloses a putter head with a U-shaped body and a block within the middle. The block has a lower specific gravity than the U-shaped body.

Yet another example is Rose et al., U.S. Pat. No. 5,951,412 originally filed in January of 1996 for a Golf Club, Particularly A Putter. The Rose patent discloses a center portion composed of a light metal material and the heel and toe portions composed of heavier metals. The metals are forged or cast to create the putter head.

Another example is Fernandez, U.S. Pat. No. 4,793,616 for a Golf Club, which was originally filed in 1984, discloses a lightweight composite material molded to a hard, high density material for distribution of mass. Fernandez discloses a composite shell with a high density insert composed of tungsten or some other high density material.

Fisher, U.S. Pat. No. 6,695,708 for a Golf Putter With Polyhedral Head And Rotatably Selectable Traction Control Faces, discloses a putter with two faces of different ball impacting characteristics.

Although these inventions have provided new and improved putters for making the game of golf more enjoyable for high handicap players, the prior art has not optimized a putter by making it easily interchangeable from on striking surface to another while providing greater stability.

BRIEF SUMMARY OF THE INVENTION

The present invention discloses a putter with an extendable removable central shaft portion which allows for better club length fitting to a golfer while maintaining the putters swing weight.

One aspect of the present invention is a putter-type golf club including a club head, a central shaft portion and an upper shaft portion. The club head has a hosel and a lower shaft portion extending from the hosel. The lower shaft portion has a top end. The central shaft portion has a bottom end and a top end. The bottom end of the central shaft portion is removably connected to the top end of the lower shaft portion. The upper shaft portion has a grip end and a bottom end. The bottom end of the upper shaft portion is removably connected to the top end of the central shaft portion. The central shaft portion is selected from a plurality of central shaft portions, each of the plurality of central shaft portions having a mass within ten grams of any other of the plurality of central shaft portions, and each of the plurality of central shaft portions having a length that is different than any other of the plurality of central shaft portions.

Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a top perspective view of a putter-type club head.

FIG. 2 is a bottom plan view of putter-type club head of FIG. 1.

FIG. 3 is a top plan view of putter-type club head of FIG. 1.

FIG. 4 is a front plan view of putter-type club head of FIG. 1.

FIG. 5 is a heel side plan view of a body of the putter-type club head of FIG. 1.

FIG. 6 is an exploded bottom view of the putter-type club head of FIG. 1.

FIG. 7 is a top perspective view of an alternative embodiment of a putter-type club head.

FIG. 8 is a top perspective view of an alternative embodiment of a putter-type club head.

FIG. 9 is an isolated view of one embodiment of an alignment means for a putter-type club head.

FIG. 10 is an isolated view of one embodiment of an alignment means for a putter-type club head.

FIG. 11 is an isolated view of one embodiment of an alignment means for a putter-type club head.

FIG. 12 is a comparison of three different central shaft portions connected to lower and upper shaft portions.

FIG. 13 is an isolated view of a central shaft portion having a first length.

FIG. 14 is an isolated view of a central shaft portion having a second length.

FIG. 15 is an isolated view of a central shaft portion illustrating the mass member.

FIG. 18 is a front plan view of a putter.

FIG. 19 is a side view of the putter of FIG. 18.

FIG. 20 is a front plan view of a putter.

FIG. 21 is a side view of the putter of FIG. 20.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, a putter-type golf club 100 includes a putter-type golf club head 20, a shaft 102 and a grip 104. The putter-type golf club 100 has a central shaft portion 200 which is preferably removably connected to a lower shaft portion 201 and an upper shaft portion 202. Alternatively, the central shaft portion 200 is permanently connected to the lower shaft portion 201 and upper shaft portion 202.

The central shaft portion 200 is selected from a plurality of central shaft portions 200 in order to allow for the length of the putter-type golf club 100 to be fit to a particular golfer. Although the length of each of the plurality of central shaft portions 200 varies, the mass of each of the plurality of central shaft portions 200 is substantially the same, and preferably does not exceed a 10 grams variance, more preferably a 5 grams variance, and even more preferably a 1 gram variance. In this manner, the swing-weight of the putter-type golf club 100 is maintained even though the length may be decreased or increased.

As shown in FIG. 12, each of the central shaft portions 200, 200′ and 200″ have a different length, but the length of the lower shaft portion 201 and the upper shaft portion 202 remains the same. The length of each of the central shaft portions 200 preferably varies for 0.5 inch to 5 inches, more preferably from 0.0 inch to 3 inches. The central shaft portion 200 may also be used for long club length and mid-club length putters as discussed below.

As shown in FIGS. 13 and 14, the central shaft portion has a bottom body 210, main body 211 and a top body 212. Ina preferred embodiment, the length of the main body 210 changes for each of the plurality of central shaft portions while the length of the bottom body 210 and the top body 212 both remain the same.

As shown in FIG. 15, the central shaft portion 200 has a top end 216 and a bottom end 217. The top end 216 is connected to the bottom end of the upper shaft portion 202 and the bottom end 217 is connected to the top end of the lower shaft portion 201. Each of the top body 212 and the bottom body 210 preferably has a plurality of threads 215 for threadingly connecting the central shaft portion 200 to the lower and upper shaft portions 201 and 202. Those skilled in the pertinent art will recognize other connection methods that may be used without departing from the scope and spirit of the present invention. In an alternative embodiment, the central shaft portion 200 is permanently connected to the other shaft portions 201 and 202 using a snap-fit connection or the like.

Also shown in FIG. 15 is a mass member 213 which is preferably disposed within the interior of the central shaft portion 200, preferably on the interior wall of the main body 211. The mass member 213 varies in mass between the plurality of central shaft portions 200 allowing for the swing-weight to remain constant even though the length varies. If the central shaft portion 200 is composed of graphite, then the mass member 213 is preferably composed of plies of pre-preg with a heavy mass material such as tungsten doped polymers disposed within the plies. In this manner, mass is added the mass members 213 of the shorter central shaft portions 200 to maintain the constant swing-weight.

FIG. 16 further illustrates a preferred embodiment of the mass member 213. The mass member 213 has a body 221 with a plurality of weights 222 integrated therein. The mass member preferably has a mass ranging from 0.5 grams to 50 grams, more preferably from 1 grams to 20 grams, and more preferably from 1 gram to 10 grams.

FIG. 17 is a flow chart of a method of the invention. The method 400 begins at block 402 with swinging a first putter 100 having a first length and a first central shaft portion 200. At block 404, the first central shaft portion 200 is exchanged with a second central shaft portion 200′ having a different length but substantially same mass. At block 406, the golfer swing the putter with the second central shaft portion, and now with a second length that is different than the first length even though the mass of the putter 100 remains the same.

The club head 20 may be any type of putter-type club head. A preferred club head 20 is shown in FIGS. 1A-11. The club head 20 preferably includes a body 22 and a peripheral mass belt 23. In a preferred embodiment, the body 22 is composed of a material having a density ranging from 0.90 g/cm³ to 6.0 g/cm³. A preferred metal for the body 22 is an aluminum alloy. Alternative materials for the body 22 include aluminum, titanium, titanium alloys, magnesium, magnesium alloys, and the like. The body 22 is preferably formed as a single cast structure using known investment casting techniques. However, those skilled in the pertinent art will recognize that alternative forming techniques such as milling, welding forged or formed pieces, and the like may be utilized without departing from the scope and spirit of the present invention.

The body 22 preferably weighs from 100 grams to 300 grams, more preferably from 150 grams to 200 grams, even more preferably from 160 grams to 180 grams and most preferably 170 grams.

The peripheral mass belt 23 is preferably composed of a material that has a density greater than the density of the material of the body 22. In a preferred embodiment, the peripheral mass belt 23 is composed of a material having a density ranging from 6.0 g/cm³ to 20.0 g/cm³, and more preferably from 7.0 g/cm³ to 10.0 g/cm³. In a preferred embodiment, the peripheral mass belt 23 is composed of stainless steel. In alternative embodiments, the peripheral mass belt 23 is composed of zinc, brass, copper, gold, silver, tungsten, tungsten-based alloys, iron-based alloys, and copper-based alloys.

The peripheral mass belt 23 preferably weighs from 100 grams to 300 grams, more preferably from 150 grams to 200 grams, even more preferably from 160 grams to 180 grams and most preferably 170 grams. In a most preferred embodiment, the body 22 and the peripheral mass belt 23 have the same mass or substantially the same mass. The club head 20 preferably has a mass ranging from 250 grams to 500 grams, more preferably from 300 grams to 400 grams, and most preferably 340 grams.

In a preferred embodiment, the body 22 has a face portion 24, a crown portion 26, a sole portion 28 and a column portion 30. The face portion 24, the crown portion 26, the sole portion 28, the column portion 30 and the peripheral mass belt 23 define a central aperture 32 that extends through the body 22. The central aperture 32 has a heel opening 34 at a heel end 27 of the body 22 and a toe opening 36 at a toe end 25 of the body 22. The central aperture 32 horizontally separates the face portion 24 from the peripheral mass belt 23, and the central aperture 32 vertically separates the crown portion 26 from the sole portion 28. The central aperture 32, in connection with the peripheral mass belt 23, allows for the center of gravity of the club head 20, CG, to be moved rearward from the face portion 24. In a preferred embodiment, the CG of the club head 20 is positioned within the central aperture 32, and thus the CG is not positioned within material of the club head 20 but instead the CG lies outside the material in space within the central aperture 32. Preferably, the CG is located between 0.25 inch and 1.0 inch from an external surface 71 of the sole portion 28, more preferably 0.50 inch to 0.75 inch, and most preferably 0.73 inch from the external surface 71 of the sole portion 28. Also, preferably the CG of the club head 20 is located 0.50 inch to 2.5 inches rearward from the external surface 58 of the face portion 24, more preferably 0.75 inch to 1.5 inches, and most preferably 0.944 inch from the external surface 58 of the face portion 24.

In addition to assisting in the rearward positioning of the CG, the peripheral mass belt 23 is a rearward support structure for crown portion 26. The peripheral mass belt 23 preferably ranges from 20 to 50 volume percent of the club head 20 and ranges from 40 to 75 weight percent of the club head 20.

The sole portion 28 preferably has an approximate T-shape. The external surface 71 of the sole portion 28 contacts the ground when the club head 20 is used with a shaft and grip, both not shown, as a putter. The CG of the club head 20 preferably lies above the sole portion 28.

The crown portion 26 extends rearward from the face portion 24. The crown portion 26 has a central elongated section 44 and a front section 46. The front section 46 has a width w′ that extends from the heel end 23 to the toe end 25 of the face portion 24, and gradually narrows as the front section 46 transitions into the central elongated section 44. The width, w′, preferably ranges from 2.5 inches to 5.0 inches, more preferably from 3.5 inches to 4.5 inches, and most preferably 4.25 inches. The central elongated section 44 has a width w″ that is less than the width w′ of the front section 46. The width, w″, preferably ranges from 1.0 inch to 3.0 inches, more preferably from 1.5 inches to 2.25 inches, and most preferably 1.8 inches. The internal surface 48 of the crown portion 26 partially defines the central aperture 32. The crown portion preferably has a thickness that ranges from 0.10 inch to 0.50 inch, more preferably 0.15 inch to 0.30 inch.

The external surface 38 of the crown portion 26 preferably has an alignment means 40 thereon. The external surface 38 also preferably has a cylindrical rod 54 extending upward therefrom for engagement with a shaft, not shown. As shown in FIGS. 7 and 8, a preferred alignment means 40 is first and second inserts 40 a and 40 b disposed within first and second recesses in the crown portion 26. The depth of each of the recesses is preferably within 0.05 inch to 0.50 inch, more preferably 0.1 inch to 0.250 inch. Each of the circular inserts 40 a and 40 b preferably have a thickness ranging from 0.05 inch to 0.50 inch, more preferably 0.1 inch to 0.250 inch.

In a preferred embodiment, each of the circular inserts 40 a and 40 b are preferably composed of a thermosetting polyurethane material such as described in U.S. Pat. No. 6,273,831, entitled Golf Club Head with A Polymer Insert, assigned to Callaway Golf (the assignee of the Present Application), which is hereby incorporated by reference in its entirety. Alternatively, each of the circular inserts 40 a and 40 b may be composed of a thermoplastic polyurethane. Each of the circular inserts 40 a and 40 b is preferably colored white, through painting or doping of the polyurethane with coloring agents, and each circular insert 40 a and 40 b preferably has a texture of a golf ball cover. Each of the circular inserts 40 a and 40 b preferably has a diameter ranging from 1.62 inches to 1.70 inches, and most preferably 1.68 inches. Those skilled in the art will recognize that more than two circular inserts 40 a and 40 b may be utilized without departing from the scope and spirit of the present invention.

Alternative alignment means are disclosed in U.S. Pat. No. 4,688,798, entitled Golf Club And Head Including Alignment Indicators, assigned to the Callaway Golf (the assignee of the Present application), which pertinent parts are hereby incorporated by reference. As disclosed in U.S. Pat. No. 4,688,798, the alignment means assists a golfer in properly aiming a golf ball toward a hole when putting. Alternative alignment means, including a large white strip may be utilized in the present invention.

FIGS. 9-11 illustrate various alignment means 40 for the club head 20. In these embodiments, the alignments means is a relatively flat strip of a composite material or a thermoplastic material which is placed within a recess, not shown, in the crown portion 26 of the body 22.

Other examples of such putter-type golf club heads which may be used in the putter type golf club 100 are described in the following U.S. patents, all of which are hereby incorporated by reference in their entireties: Byrne et al., U.S. Pat. No. 6,878,074, for a Golf Club Head Composed of a Damascene Patterned Metal; Dewanjee et al., U.S. Pat. No. 6,893,358, for a Putter-Type Golf Club Head With An Insert; Tang et al, U.S. Pat. No. 6,905,420, for a Putter Head; Dewanjee et al. U.S. Pat. No. 6,971,960, for an Insert For Golf Club Head; Tang et al., U.S. Pat. No. 6,974,394, for a Putter Head; Hettinger et al., U.S. Pat. No. 6,984,181, for a Multiple Material Golf Putter Head; Breier et al., U.S. Pat. No. 7,048,648, for a Putter-Type Golf Club Head With An Insert.

An alternative embodiment of a putter 100 is shown in FIGS. 18-21, which also illustrate a reference frame for measuring the center of gravity of the putter 100, which is different than the center of gravity for the club head 20. The putter 100 generally includes the putter club head 20, a shaft 102 and a grip 104. In one embodiment, the putter 100 has a conventional club length that preferably ranges from 33 inches to 36 inches, and a mass that preferably ranges from 475 grams to 525 grams.

In another embodiment, the putter 100 has a mid-club length that preferably ranges from 41 inches to 45 inches, and a mass that preferably ranges from 665 grams to 700 grams. In this mid-length embodiment, the shaft 102 preferably has a mss that ranges from 160 grams to 175 grams and the grip 104 preferably has a mass that ranges from 135 grams to 145 grams. The loft angle is preferably three degrees and the lie angle is preferably 72 degrees.

In yet another embodiment, the putter 100 has a long-club length that preferably ranges from 46 inches to 50 inches, and a mass that preferably ranges from 730 grams to 775 grams. In this long-length embodiment, the shaft 102 preferably has a mass that ranges from 160 grams to 175 grams. This long-length embodiment preferably has two grips 104 (the second grip not shown) with the top grip 104 preferably having a mass that ranges from 45 grams to 50 grams, and a bottom grip (not shown) having a mass that preferably ranges from 95 grams to 105 grams. The loft angle is preferably three degrees and the lie angle is preferably 78 degrees.

From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims. 

1. A putter-type golf club comprising: a club head having a hosel and a lower shaft portion extending from the hosel, the lower shaft portion having a top end; a central shaft portion having a bottom end and a top end, the bottom end of the central shaft portion removably connected to the top end of the lower shaft portion; and an upper shaft portion having a grip end and a bottom end, the bottom end of the upper shaft portion removably connected to the top end of the central shaft portion; wherein the central shaft portion is selected from a plurality of central shaft portions, each of the plurality of central shaft portions having a mass within ten grams of any other of the plurality of central shaft portions, and each of the plurality of central shaft portions having a length that is different than any other of the plurality of central shaft portions.
 2. The putter-type golf club according to claim 1 wherein the plurality of central shaft portions comprises having a first central shaft portion having a length of 4 inches and a second central shaft portion having a length of 6 inches.
 3. The putter-type golf club according to claim 1 wherein each of the plurality of central shaft portions comprises a mass member disposed within an outer wall, the mass member having a mass ranging from 5 grams to 35 grams.
 4. The putter-type golf club according to claim 1 wherein each of the plurality of central shaft portions comprises a main body having a first outer diameter value, a top body having a second outer diameter value less than the first outer diameter value, and a bottom body having a third outer diameter value less than the first outer diameter value.
 5. The putter-type golf club according to claim 4 wherein the length of the top body of each of the plurality of central shaft portions is the same, and the length of the bottom body of each of the plurality of central shaft portions is the same.
 6. The putter-type golf club according to claim 1 further comprising a grip attached to the upper shaft portion.
 7. The putter-type golf club according to claim 1 wherein the central shaft portion is threadingly connected to the lower shaft portion and the upper shaft portion.
 8. The putter-type golf club according to claim 1 wherein the lower shaft portion, the upper shaft portion and the central shaft portion are composed of a graphite material.
 9. The putter-type golf club according to claim 1 wherein the lower shaft portion, the upper shaft portion and the central shaft portion are composed of a steel material.
 10. A method of fitting a putter-type golf club to a golfer, the method comprising: putting with the putter-type golf club having a first length, the putter-type golf club having a removable first central shaft portion; exchanging the first central shaft portion with a second central shaft portion, the second central shaft portion having a length that is different than the length of the first central shaft portion and a mass within ten grams of the first central shaft portion, wherein the swing-weight of the putter-type golf club remains substantially the same; putting with the putter-type golf club having the second central shaft portion and a second length that is different than the first length. 